Archbishop Ambrose De Paoli, Apostolic Nuncio to Australia, Sydney's Cardinal George Pell, and Bishop of Darwin Ted Collins will concelebrate the Mass, according to an Adelaide archdiocesan statement.

Readers will include South Australia's Chief Justice John Doyle, a Saint Ignatius College old scholar. ABC newsreader Michael Smyth and Channel Seven journalist and presenter Rosanna Mangiarelli will commentate.

A special hymn has also been written for the event by Jesuit composer Christopher Willcock, using a prayer composed by the former General of the Society, Pedro Arrupe.

Fr O'Kelly's ordination, appointed Auxiliary Bishop in July, will see him become the first Jesuit elevated to such a position in Australia in a year that marks 150 years of Jesuit education in South Australia and the Jubilee of St Francis Xavier.

"Our Province did not expect to be separated from someone of Greg's talents and leadership," Australian Jesuit provincial Fr Mark Raper says. "Yet we know the Catholic and wider community in Adelaide will benefit greatly from Greg's service in this crucial support role to Archbishop Wilson."

Fr Raper said he was confident that Fr O'Kelly will serve the Church in Adelaide with all his energy, and that he brings great experience and pastoral gifts to the role.

"Our prayers and support are with him always," Fr Raper said.

Fr O'Kelly, 64, who was awarded an Order of Australia for services to education in the 1994, was Headmaster of Saint Ignatius' College for 12 years. Fr O'Kelly entered the Society of Jesus in 1959 and was ordained to the priesthood in 1972.